In many of the cryptography applications like password or IP address
encryption schemes, symmetric cryptography is useful. In these relatively
simpler applications of cryptography, asymmetric cryptography is difficult to
justify on account of the computational and implementation complexities
associated with asymmetric cryptography. Symmetric schemes make use of a single
shared key known only between the two communicating hosts. This shared key is
used both for the encryption as well as the decryption of data.